An indispensable part of the dental operatory equipment is the dental air/water/spray syringe. A conventional air/water/spray syringe includes a hand piece or handle, a pair of buttons and a nozzle which normally includes a central port or orifice for emitting water, a plurality of peripheral orifices generally spaced 120.degree. from each other for emitting air. The two buttons are selectively operable for controlling the emission of air alone, water alone, or both in the form of a spray or a mist. Such an air/water/spray syringe is used almost every time a dentist provides care for a patient, whether it is only by way of a dental examination or actual treatment. Frequently a dentist may direct air to dry an area moist with saliva or blood for better visibility, or may direct an air/water/spray or jet to clean debris. Also, the prevailing use of adhesive resins has become an essential part of practicing dentistry, and before applying such adhesive resins, the tooth surface is "conditioned" (etched) by applying an acid, such as phosphoric acid, for varying periods of time. Such acid must be flushed by directing a pin point copious water spray to the area for at least sixty (60) seconds. During this time the dentist has to keep his eye on the very spot to be rinsed to insure that proper rinsing has been achieved. During such pressurized application of air/water or an air/water spray into the mouth of a patient, the latter and any entrained admixed material can be reflected outwardly toward the dentist/operator/assistant. Such reflection outwardly from a patient's mouth is particularly common during cavity preparation due to the very nature of this operation. Prior to placing the filling material into the prepared tooth cavity, air and/or water is directed into the prepared cavity to cleanse and dry ,the same, and the cavity itself reflects the latter fluid and any materials admixed therewith back toward the operator's/dentist's/assistant's neck, eyes or the like. Such reflected admixed fluid might well be a mixture of saliva, blood, acid or similar debris. Needless to say, the latter creates a significant and serious risk, particularly in this day and age of presently incurable communicable diseases, such as AIDS (Acquired Immune Deficiency Syndrome) as the end effect of HIV (Humanimmuno Deficiency Virus).
U.S. Pat. No. 4,424,036 issued on Jan. 3, 1984 in the name of Oddvin Lokken discloses an anti-splash device for attachment to a dental tool which delivers water from the head thereof during use. The anti-splash device is an elongated, hollow member which includes an interior member for securing the hollow member to the head of the dental tool. The hollow member is thus in surrounding relationship to and spaced from the water delivery apparatus, and though it intends to provide anti-splash functions, the very construction thereof and particularly the space between the anti-splash device and the dental tool prevents optimum intended functioning thereof.
U.S. Pat. No. 4,611,992 issued on Sep. 16, 1986 to Oddvin Lokken discloses another anti-splash device which is also attached to a dental tool which delivers an aqueous fluid from a nozzle. The anti-splash device is an inverted U-shaped member having a base and integral opposed legs depending therefrom. One of the legs has a bore through which the nozzle of the dental tool projects and the base provides an area through which an associated tooth can be viewed. The U-shaped nature of this anti-splash device prevents the aqueous fluid from being directed at all desired portions of an associated tooth, particularly posterior regions thereof, due to the existence of the depending leg opposite the nozzle. Thus, while a degree of anti-splash is certainly provided by this device, its usefulness is suspect.
Other patented dental devices of lesser interest include U.S. Pat. Nos. 2,720,702 in the name Hyman Freedman, 2,731,722 in the name of Jesse Wilen, 3,909,867 in the name Gunnar Hogsell and 4,850,868 in the name of Gerard Wright et al.